Cal. Labor Code § 1773.4

Any prospective bidder or his representative, any representative of any craft, classification or type of workman involved, or the awarding body may, within 20 days after commencement of advertising of the call for bids by the awarding body, file with the Director of Industrial Relations a verified petition to review the determination of any such rate or rates upon the ground that they have not been determined in accordance with the provision of Section 1773 of this code. Within two days thereafter, a copy of such petition shall be filed with the awarding body. The petition shall set forth the facts upon which it is based. The Director of Industrial Relations or his authorized representative shall, upon notice to the petitioner, the awarding body and such other persons as he deems proper, including the recognized collective bargaining representatives for the particular crafts, classifications or types of work involved, institute an investigation or hold a hearing. Within 20 days after the filing of such petition, or within such longer period as agreed upon by the director, the awarding body, and all the interested parties, he shall make a determination and transmit the same in writing to the awarding body and to the interested parties. Such determination shall be final and shall be the determination of the awarding body. Upon receipt by it of the notice of the filing of such petition the body awarding the contract or authorizing the public work shall extend the closing date for the submission of bids or the starting of work until five days after the determination of the general prevailing rates of per diem wages pursuant to this section. Upon the filing of any such petition, notice thereof shall be set forth in the next and all subsequent publications by the awarding body of the call for bids. No other notice need be given to bidders by the awarding body by publication or otherwise. The determination of the director shall be included in the contract.